1. Field of the Invention
The present invention relates to storage area networks and, more particularly, to implementing zones in networks such as Fibre Channel networks.
2. Background of the Invention
Storage area networks or SANs provide an increasingly important mechanism for making shared storage available to multiple hosts. A SAN typically includes a number of storage devices, a plurality of Hosts, and a number of Switches arranged in a Switching Fabric that connects the storage devices and the Hosts.
Most SANs rely on the Fibre Channel protocol for communication within the Fabric. For a detailed explanation of the Fibre Channel protocol and Fibre Channel Switching Fabrics and Services, see the materials on Fibre Channel provided by the Technical Committee T11, which is the committee within INCITS responsible for Device Level Interfaces (www.T11.org), all incorporated by reference herein for all purposes.
Fibre Channel based SANs are often organized into zones. Within each zone, Hosts can see and access only storage devices or other hosts belonging to that zone. This allows the coexistence on the same SAN of different computing environments. For example, it is possible to define on a SAN a Unix zone and a separate Windows zone. Unix servers in the Unix zone may access only storage or hosts devices within the Unix zone, and do not interfere with the other devices connected to the SAN. In the same manner, Windows servers belonging to the Windows zone may access storage or host devices only within the Windows zone, without interfering with the other devices connected to the SAN. In another example, one zone may be defined for an engineering group and a second zone may be defined for a human resources group within a single company. The SAN administrator is responsible for defining the particular zones in a SAN, as required or dictated by the computing and storage resources connected to it. The Switching Fabric allows communications only between devices belonging to the same zone, preventing a device of one zone from seeing or accessing a device of another zone. A host for example can access a storage device in another zone only if that storage device happens to also be in the same zone as the host.
In large storage area networks having many hosts and storage devices, it can be particularly challenging to efficiently implement zoning. It would be desirable to have more advanced zoning implementations to meet this challenge.